The lawsuit, submitted to the Competition Appeal Tribunal, claims that Microsoft is punishing thousands of UK businesses and organisations that use rival cloud computing services from Amazon, Google and Alibaba by forcing them to pay higher licence fees for Windows Server.

It is an “opt-out” collective action being brought by Dr Maria Luisa Stasi and law firm Scott+Scott.

Dr Stasi said: “Put simply, Microsoft is punishing UK businesses and organisations for using Google, Amazon and Alibaba for cloud computing by forcing them to pay more money for Windows Server.

“By doing so, Microsoft is trying to force customers into using its cloud computing service Azure and restricting competition in the sector.

“This lawsuit aims to challenge Microsoft’s anti-competitive behaviour, push them to reveal exactly how much businesses in the UK have been illegally penalised, and return the money to organisations that have been unfairly overcharged.”

Scott+Scott UK partner James Hain-Cole, leading on the case, said: “Collective actions level the playing field and allow organisations to fight back against anti-competitive behaviour from some of the biggest companies in the world.

“Dr Stasi’s case against Microsoft aims to do exactly that. We are proud to support her efforts to secure compensation for the class and hold Microsoft to account for its conduct that affects businesses and organisations across the UK economy.”